THIS INVENTION relates to rolling apparatus for rolling of turf or grass surfaces such as golfing greens and bowling greens.
Conventional rolling apparatus is described in International Publication WO93/19582 and comprises a mobile main frame and an undercarriage having at least three ground contacting or smoothing rollers which are unevenly spaced, said undercarriage being pivotally attached by a universal pivot joint to the main frame wherein the undercarriage is pivotabie with respect to the main frame in any direction The main frame includes a ground engaging roller driven by drive means located on the main frame. The main frame is driven in a line of travel normal to the longitudinal axis of any one of the three smoothing rollers which were all oriented parallel to each other.
A similar arrangement to the rolling apparatus described above is described in AU 522301 with the fundamental difference however, being that in this reference, the three smoothing rollers were evenly spaced rather than being unevenly space as described in International Publication WO93/119582. Also, in Australian Patent 522301, there was provided coupling means between the undercarriage and the main frame which only allowed pivotal movement of he undercarriage with respect to the main frame about a longitudinal axis parallel to the direction of travel of the rolling apparatus and not about a horizontal axis normal to the direction of travel.
However, disadvantages that occurred in relation to the rolling apparatus described in both International Publication WO93/19532 and Australian Patent 522301 was in regard to rolling or smoothing of lawns that had an undulating or uneven surface. Such disadvantages included the following:
(i) in some cases, the three ground contacting rollers did not contact the surface of the lawn because of its uneven surface thereby impairing rolling efficiency of the rolling apparatus which necessitated repeated rolling operations to create an even, smooth surface; and
(ii) the direction of rolling had to be carefully chosen to achieve an efficient rolling or smoothing operation, If the direction of rolling was inappropriate, then again it was necessary to carry out further or repeated rolling operations.
It was also found, in regard to conventional rolling apparatus as described above, that sometimes the smoothing rollers left indentation lines on lawns having an even surface as well as lawns having an uneven surface. Such indentation lines were unsightly and detrimental to achievement of a smooth and even grass surface.
Another disadvantage of conventional rolling apparatus as described above was that surface corrugations still remained in lawns in some cases after repeated rolling operations.
It therefore is an object of the invention to provide rolling apparatus that may alleviate one or more of the abovementioned disadvantages of the prior art
The invention, therefore, provides rolling apparatus for the rolling of turf or grass surfaces which include a mobile main frame and at least a pair of undercarriages attached to the main frame in side-by-side relationship wherein each undercarriage has one or more smoothing rollers and there is further provided a control arm or plate pivotally attached to the main frame about a horizontal axis wherein each undercarriage is pivotally attached to the control arm or plate and a transmission interconnecting each undercarriage to an operating lever or joystick wherein actuation of the operating lever or joystick causes reciprocatable pivotal movement of each undercarriage such that, in use the or each smoothing roller closely follows ground contours.
Preferably the control arm is pivotally attached to an undersurface of the main frame or undersurface of a frame member of the main frame. To this end, therefore, a pivot joint may be provided interconnecting the control plate or arm and the main frame which has a pivot pin pivotable about a horizontal axis which is accommodated in bushes or other suitable forms of bearings attached to the control arm and the main frame.
Each undercarriage may be formed in any suitable manner and may, for example, comprise a pair of opposed end frames or end plates interconnecting an intermediate plate or web forming the main body of the undercarriage. Thus, each undercarriage may be channel shaped, such as being U- or V-shaped or alternatively, may comprise an undercarriage plate omitting end frames or end plates, which undercarriage plate is oriented in a substantially horizontal plane in use. Suitably each end frame or plate may have rotatably mounted thereto the one or more smoothing rollers. Preferably there is provided a plurality of smoothing rollers which may be unevenly spaced or evenly spaced. Most preferably there are provided three smoothing rollers.
Each undercarriage is preferably pivotably attached to the control arm so as to be pivotable about a vertical axis. Preferably each undercarriage is pivotable universally about the vertical axis and this may be achieved by a universal pivot joint, such as a ball in socket, for example, or by each undercarriage having a spherical bearing interposed between an upright stud and an outer bearing housing.
Each of the three smoothing rollers may include a longitudinal axle extending the length of each roller which is attached to each end to an associated end frame or plate or alternatively, may be provided with stub axles at each end attached to an associated end frame or plate. Suitably each of the three smoothing rollers are substantially parallel with each other.
The main frame or chassis may overlie each undercarriage and the control arm. The main frame which is mobile may also support or carry at least one main ground contacting roller. There also may be provided drive means which is drivingly connected to the main roller for propelling or driving the rolling apparatus in a line of travel which is suitably normal to the longitudinal axis of at least one of the smoothing rollers.
Preferably a similar drive means may be utilized as described in Australian Patent 522301 which is mounted on the main frame. However, this is not essential and any suitable drive means may be utilized wherein an engine or motor, suitably of the internal combustion type, is mounted on a top surface of the main frame or chassis.
The motor may have an output shaft drivingly connected to the drive roller of the main frame via suitable gear means or belt-pulley mechanism.
The main frame is suitably supported by opposed ground engaging wheels located on each side thereof and suitably attached to the main frame by stub axles or other suitable axle means There also may be provided means for raising or lowering the ground engaging wheels when required for transportation or storage as described in International Publication WO93/19582.
Alternatively, raising or lowering of the wheels may be achieved as described in Australian Patent 522301.
In a preferred embodiment of the invention, there may be provided a pair of undercarriages which are each pivotally attached to the main frame or chassis along one side or one end thereof. One undercarriage may travel on level ground and the other undercarriage may traverse an inclined or oblique ground surface as shown in the drawings herein.
In another embodiment of the invention, there may be provided four or even six undercarriages which are each attached to the control arm as described above.
In each of the abovementioned embodiments the operating lever or joystick may be accessible to the driver of the rolling apparatus who may be located in a seat attached to an upper surface of the main frame. Preferably rotational movement of the joystick as a result of the interconnecting transmission causes reciprocatable pivotal movement of each undercarriage. In one form, this may be accomplished by an actuating arm interconnecting the joystick or extension or appendage thereof which moves in a reciprocatable fashion thereby causing its adjacent undercarriage, which is attached to the actuating arm, to also move in similar fashion. Also in this arrangement, each member of a pair of undercarriages may be interconnected by an appropriate linkage mechanism to ensure that once reciprocatable movement of one undercarriage is initiated then corresponding movement of the adjacent undercarriage may also occur, This may be achieved, for example, by the linkage mechanism having a linkage rod pivotally connected to pivot joints mounted to the chassis which undergoes reciprocatable movement after initial reciprocatable movement of the undercarriage having the actuating arm directly attached thereto. An example of such linkage mechanism is illustrated herein.